The present invention generally relates to a twist lock shoe sole system. More specifically, the present invention relates to a shoe sole system with interchangeable shoe soles which are selectively detachable from a shoe midsole via a twist lock mechanism.
Shoes having replaceable soles are well-known in the prior art. Several examples of such structures are disclosed in U.S. Pat. Nos. 7,520,069 and 6,813,847. The mechanism by which the replaceable soles attach to the shoe uppers vary. For example, shoes exist in the marketplace with sole cavities designed to receive one of various sole plates. The various sole plates include different tread patterns thereon. Further, many such shoes further include a strap on the rear side of the sole plate which is attachable to a portion of the shoe upper, at the heel of the shoe.
However, many products available on the market have problems with maintaining the engagement between the sole plate and the shoe upper in some conditions. For example, when walking through mud or other so-called “sloppy” terrain, the sole plate may be pulled from its engagement with the shoe upper. When lifting a foot from the mud, suction may act on the sole plate, thereby causing an unwanted release of the sole plate from the shoe upper.
Therefore, a better mechanism for selectively engaging the shoe sole with the shoe upper/midsole is needed.